Image forming apparatus, sheet type determination method and program in the apparatus

Patent metadata

Field	Value
Publication number	US-10962913-B2
Application number	US-202016923262-A
Country	US
Kind code	B2
Filing date	Jul 8, 2020
Priority date	Aug 16, 2019
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

An image forming apparatus includes: a sheet feeding tray that stores a sheet; a sheet thickness measurement device that measures a sheet thickness of the sheet fed from the sheet feeding tray; a hardware processor that: determines a type of the sheet of which the sheet thickness is measured, a sheet type associated with each of sheet thickness ranges, and the sheet thickness measured by the sheet thickness measurement device; and adjusts a first sheet thickness range by expanding the first sheet thickness range to at least one of an upper limit value side or a lower limit value side; and an image former that forms an image on the sheet fed from the sheet feeding tray under image forming conditions corresponding to the sheet type determined by the hardware processor.

First claim

What is claimed is:

1. An image forming apparatus comprising:
a sheet feeding tray that stores a sheet;
a sheet thickness measurement device that measures a sheet thickness of the sheet fed from the sheet feeding tray;
a hardware processor that:
determines a type of the sheet of which the sheet thickness is measured, on a basis of a plurality of sheet thickness ranges set in advance, a sheet type associated with each of the sheet thickness ranges, and the sheet thickness measured by the sheet thickness measurement device; and
adjusts a first sheet thickness range by expanding the first sheet thickness range to at least one of an upper limit value side or a lower limit value side, in a case where a second sheet thickness measurement is performed by the sheet thickness measurement device after a first sheet thickness measurement by the sheet thickness measurement device in an identical job, by performing at least one of processing of adding a predetermined amount of adjustment to an upper limit value of the first sheet thickness range including a first sheet thickness measured by the first sheet thickness measurement to obtain an adjusted upper limit value, or processing of subtracting a predetermined amount of adjustment from a lower limit value of the first sheet thickness range to obtain an adjusted lower limit value; and

an image former that forms an image on the sheet fed from the sheet feeding tray under image forming conditions corresponding to the sheet type determined by the hardware processor, wherein
the hardware processor determines the type of the sheet on which the second sheet thickness measurement is performed, by applying an adjusted sheet thickness range by the hardware processor instead of the first sheet thickness range.

2. The image forming apparatus according to claim 1 , wherein the hardware processor adjusts the first sheet thickness range in a case where a difference between the first sheet thickness and the upper limit value or the lower limit value is less than or equal to a predetermined value, and also adjusts the upper limit value side of the first sheet thickness range in a case where the difference between the first sheet thickness and the upper limit value is less than or equal to the predetermined value, and adjusts the lower limit value side of the first sheet thickness range in a case where the difference between the first sheet thickness and the lower limit value is less than or equal to the predetermined value.

3. The image forming apparatus according to claim 1 , wherein the hardware processor adjusts the upper limit value side of the first sheet thickness range in a case where the difference between the first sheet thickness and the upper limit value is smaller than the difference between the first sheet thickness and the lower limit value, and adjusts the lower limit value side of the first sheet thickness range in a case where the difference between the first sheet thickness and the lower limit value is smaller than the difference between the first sheet thickness and the upper limit value.

4. The image forming apparatus according to claim 1 , further comprising
a table in which the sheet type is defined for each of the plurality of sheet thickness ranges, wherein the hardware processor determines the sheet type on a basis of the table.

5. The image forming apparatus according to claim 1 , wherein the amount of adjustment is set for each of the sheet types.

6. The image forming apparatus according to claim 1 , wherein the amount of adjustment is set on a basis of a past sheet thickness measurement value.

7. The image forming apparatus according to claim 1 , further comprising a selector that allows a user to select whether or not to perform adjustment of the first sheet thickness range by the hardware processor.

8. The image forming apparatus according to claim 1 , wherein in a case where the identical job is a job that uses a plurality of the sheet feeding trays, the first sheet thickness measurement and the second sheet thickness measurement by the sheet thickness measurement device are performed for each of the sheet feeding trays.

9. The image forming apparatus according to claim 1 , wherein in a case where the identical job is a job that uses sheets of a plurality of sizes, the first sheet thickness measurement and the second sheet thickness measurement by the sheet thickness measurement device are performed for each of sheet sizes.

10. The image forming apparatus according to claim 1 , wherein in a case where third and subsequent sheet thickness measurements are further performed by the sheet thickness measurement device after the first sheet thickness measurement and the second sheet thickness measurement in the identical job, for the third and subsequent sheet thickness measurements, the hardware processor determines the sheet type by fixedly applying the sheet thickness range adjusted by the hardware processor for sheet type determination for the second sheet thickness measurement.

11. The image forming apparatus according to claim 10 , wherein
the hardware processor counts a number of sheet thicknesses that have values in the first sheet thickness range and neither the difference from the upper limit value or the lower limit value of the first sheet thickness range is less than or equal to a predetermined value, among the sheet thicknesses measured by the second and subsequent sheet thickness measurements, and
in a case where the number of sheet thicknesses counted by the hardware processor exceeds a predetermined number, the hardware processor changes the adjusted sheet thickness range to the first sheet thickness range, and applies the first sheet thickness range to subsequent sheet type determination.

12. The image forming apparatus according to claim 10 , wherein
the hardware processor counts a number of sheet thicknesses that have values in the first sheet thickness range and in which neither the difference from the upper limit value or the lower limit value of the first sheet thickness range is less than or equal to a predetermined value, among the sheet thicknesses measured by the second and subsequent sheet thickness measurements,
the hardware processor clears a count value of the hardware processor when a sheet thickness is measured that has a value in the first sheet thickness range and in which the difference from at least one of the upper limit value or the lower limit value of the first sheet thickness range is less than or equal to a predetermined value, and
in a case where the count value of the hardware processor exceeds a predetermined number after the count value of the hardware processor is cleared by the hardware processor, the hardware processor changes the adjusted sheet thickness range to the first sheet thickness range, and applies the first sheet thickness range to subsequent sheet type determination.

13. The image forming apparatus according to claim 11 , wherein
the hardware processor counts a number of sheet thicknesses that have values in the first sheet thickness range and in which the difference from the upper limit value or the lower limit value of the first sheet thickness range is less than or equal to a predetermined value, among the sheet thicknesses measured by the second and subsequent sheet thickness measurements, and
in a case where the number of sheet thicknesses counted by the hardware processor exceeds a predetermined number after the change to the first sheet thickness range is applied by the hardware processor, the hardware processor again changes the first sheet thickness range to the adjusted sheet thickness range, and applies the adjusted sheet thickness ran

Assignees

• Konica Minolta Inc

Inventors

• Kawabata Mie
• Murakawa Akira
• Kawai Atsushi

Classifications

• G03G2215/00751

  of sheet type, e.g. OHP · CPC title

• G03G15/6508

  Automatic supply devices interacting with the rest of the apparatus, e.g. selection of a specific cassette (matching the image with the size of the copy material G03G15/5095) · CPC title

• G03G15/6502 Primary

  Supplying of sheet copy material; Cassettes therefor · CPC title

• G03G15/5029 Primary

  by measuring the copy material characteristics, e.g. weight, thickness · CPC title

• G03G15/6555

  Handling of sheet copy material taking place in a specific part of the copy material feeding path · CPC title